The object of this project is to: a) identify and find solutions to those problems in basic physics, dosimetry and clincal applications associated with the use of charged particle beams in the treatment of human cancer. This will be accomplished by collaborative efforts among physicist who are actively working on projects where patients are already being treated with charged particle beams or where serious efforts are underway to develop such projects. Particular attention will be given to those investigations which will provide techniques, data and information that solve problems common to all charged particle therapy facilities, regardless of the particle employed and for which funding is not available through other institutional grants. We will: (1) carry out intercomparisons with the charged-particle calorimeter and tissue-equivalent ionization chambers at the currently active charged particle (pions, protons, helium and heavier ions) therapy facilities. (2) Establish, in a consistant manner, a measure of the radiation quality of the various heavy charged-particle therapy beams that will aid in interpretation of the intercomparisons of dosimetry, treatment planning and of the biological and clinical resuts. (3) Develop a charged particle beam dosimetry protocol that will serve as a standardizing document for all charged particle beam therapy facilities and as a guide to agencies that may oversee the quality control of charged particle beam clinical trials.